diff --git a/apps/desktop/src/components/ImageAnnotator.tsx b/apps/desktop/src/components/ImageAnnotator.tsx
index fb3a182..c8c505a 100644
--- a/apps/desktop/src/components/ImageAnnotator.tsx
+++ b/apps/desktop/src/components/ImageAnnotator.tsx
@@ -38,7 +38,10 @@ export function ImageAnnotator({ file, onCancel, onSave }: Props) {
   const [color, _setColor] = useState<AnnotatorColor>('#ef4444');
   const [width, _setWidth] = useState<AnnotatorWidth>(4);
 
-  void tool; void color; void width; void _setTool; void _setColor; void _setWidth; void redoStack;
+  const draftRef = useRef<AnnotatorOp | null>(null);
+  const [draftTick, setDraftTick] = useState(0);
+
+  void _setTool; void _setColor; void _setWidth; void redoStack;
 
   useEffect(() => {
     const url = URL.createObjectURL(file);
@@ -68,7 +71,10 @@ export function ImageAnnotator({ file, onCancel, onSave }: Props) {
     for (const op of ops) {
       renderOp(ctx, op);
     }
-  }, [imageLoaded, ops]);
+    if (draftRef.current) {
+      renderOp(ctx, draftRef.current);
+    }
+  }, [imageLoaded, ops, draftTick]);
 
   useEffect(() => {
     const onKey = (e: KeyboardEvent) => {
@@ -125,6 +131,73 @@ export function ImageAnnotator({ file, onCancel, onSave }: Props) {
     }, 'image/png');
   };
 
+  function canvasPoint(e: React.PointerEvent<HTMLCanvasElement>): { x: number; y: number } {
+    const cv = canvasRef.current!;
+    const rect = cv.getBoundingClientRect();
+    const scaleX = cv.width / rect.width;
+    const scaleY = cv.height / rect.height;
+    return {
+      x: (e.clientX - rect.left) * scaleX,
+      y: (e.clientY - rect.top) * scaleY,
+    };
+  }
+
+  const handlePointerDown = (e: React.PointerEvent<HTMLCanvasElement>) => {
+    if (!imageLoaded) return;
+    const cv = canvasRef.current;
+    if (!cv) return;
+    cv.setPointerCapture(e.pointerId);
+    const p = canvasPoint(e);
+
+    if (tool === 'text') {
+      const value = window.prompt(
+        t('app:annotator.text_prompt', { defaultValue: 'Text eingeben:' }),
+        '',
+      );
+      if (value !== null && value.trim().length > 0) {
+        setOps((cur) => [...cur, { tool: 'text', color, width, text: value, at: p }]);
+        setRedoStack([]);
+      }
+      return;
+    }
+
+    if (tool === 'pen' || tool === 'highlighter') {
+      draftRef.current = { tool, color, width, points: [p] };
+    } else {
+      draftRef.current = { tool, color, width, from: p, to: p };
+    }
+    setDraftTick((n) => n + 1);
+  };
+
+  const handlePointerMove = (e: React.PointerEvent<HTMLCanvasElement>) => {
+    if (!draftRef.current) return;
+    const p = canvasPoint(e);
+    const cur = draftRef.current;
+    if (cur.tool === 'pen' || cur.tool === 'highlighter') {
+      cur.points = [...(cur.points ?? []), p];
+    } else {
+      cur.to = p;
+    }
+    setDraftTick((n) => n + 1);
+  };
+
+  const handlePointerUp = (e: React.PointerEvent<HTMLCanvasElement>) => {
+    const cv = canvasRef.current;
+    if (cv && cv.hasPointerCapture(e.pointerId)) cv.releasePointerCapture(e.pointerId);
+    const cur = draftRef.current;
+    draftRef.current = null;
+    if (!cur) return;
+    const hasContent =
+      (cur.tool === 'pen' || cur.tool === 'highlighter')
+        ? (cur.points?.length ?? 0) >= 2
+        : !!(cur.from && cur.to && (cur.from.x !== cur.to.x || cur.from.y !== cur.to.y));
+    if (hasContent) {
+      setOps((p) => [...p, cur]);
+      setRedoStack([]);
+    }
+    setDraftTick((n) => n + 1);
+  };
+
   return (
     <div
       role="dialog"
@@ -150,7 +223,11 @@ export function ImageAnnotator({ file, onCancel, onSave }: Props) {
         {imageLoaded ? (
           <canvas
             ref={canvasRef}
-            className="max-h-full max-w-full cursor-crosshair rounded-lg border border-line/40 bg-black shadow-2xl"
+            onPointerDown={handlePointerDown}
+            onPointerMove={handlePointerMove}
+            onPointerUp={handlePointerUp}
+            onPointerLeave={handlePointerUp}
+            className="max-h-full max-w-full cursor-crosshair touch-none rounded-lg border border-line/40 bg-black shadow-2xl"
           />
         ) : (
           <p className="text-sm text-fg-muted">
@@ -188,7 +265,95 @@ export function ImageAnnotator({ file, onCancel, onSave }: Props) {
   );
 }
 
-// Stub — filled in by P4A.T2 with the actual draw switch per tool.
-function renderOp(_ctx: CanvasRenderingContext2D, _op: AnnotatorOp): void {
-  // implemented in P4A.T2
+function renderOp(ctx: CanvasRenderingContext2D, op: AnnotatorOp): void {
+  ctx.save();
+  ctx.lineCap = 'round';
+  ctx.lineJoin = 'round';
+  ctx.strokeStyle = op.color;
+  ctx.fillStyle = op.color;
+  ctx.lineWidth = op.width;
+
+  switch (op.tool) {
+    case 'pen': {
+      const pts = op.points;
+      if (!pts || pts.length < 1) break;
+      ctx.beginPath();
+      ctx.moveTo(pts[0]!.x, pts[0]!.y);
+      for (let i = 1; i < pts.length; i++) {
+        ctx.lineTo(pts[i]!.x, pts[i]!.y);
+      }
+      ctx.stroke();
+      break;
+    }
+    case 'highlighter': {
+      const pts = op.points;
+      if (!pts || pts.length < 1) break;
+      ctx.globalAlpha = 0.35;
+      ctx.lineWidth = op.width * 4;
+      ctx.beginPath();
+      ctx.moveTo(pts[0]!.x, pts[0]!.y);
+      for (let i = 1; i < pts.length; i++) {
+        ctx.lineTo(pts[i]!.x, pts[i]!.y);
+      }
+      ctx.stroke();
+      break;
+    }
+    case 'rect': {
+      const { from, to } = op;
+      if (!from || !to) break;
+      ctx.strokeRect(
+        Math.min(from.x, to.x),
+        Math.min(from.y, to.y),
+        Math.abs(to.x - from.x),
+        Math.abs(to.y - from.y),
+      );
+      break;
+    }
+    case 'circle': {
+      const { from, to } = op;
+      if (!from || !to) break;
+      const cx = (from.x + to.x) / 2;
+      const cy = (from.y + to.y) / 2;
+      const rx = Math.abs(to.x - from.x) / 2;
+      const ry = Math.abs(to.y - from.y) / 2;
+      ctx.beginPath();
+      ctx.ellipse(cx, cy, rx, ry, 0, 0, Math.PI * 2);
+      ctx.stroke();
+      break;
+    }
+    case 'arrow': {
+      const { from, to } = op;
+      if (!from || !to) break;
+      ctx.beginPath();
+      ctx.moveTo(from.x, from.y);
+      ctx.lineTo(to.x, to.y);
+      ctx.stroke();
+      const angle = Math.atan2(to.y - from.y, to.x - from.x);
+      const head = Math.max(12, op.width * 3);
+      ctx.beginPath();
+      ctx.moveTo(to.x, to.y);
+      ctx.lineTo(
+        to.x - head * Math.cos(angle - Math.PI / 6),
+        to.y - head * Math.sin(angle - Math.PI / 6),
+      );
+      ctx.moveTo(to.x, to.y);
+      ctx.lineTo(
+        to.x - head * Math.cos(angle + Math.PI / 6),
+        to.y - head * Math.sin(angle + Math.PI / 6),
+      );
+      ctx.stroke();
+      break;
+    }
+    case 'text': {
+      const { at, text } = op;
+      if (!at || !text) break;
+      const fontSize = Math.max(14, op.width * 6);
+      ctx.font = '600 ' + fontSize + 'px Inter, system-ui, sans-serif';
+      ctx.textBaseline = 'top';
+      ctx.fillText(text, at.x, at.y);
+      break;
+    }
+  }
+
+  ctx.restore();
 }